Acceleration is noticeably improved. This alone gives me great satisfaction. I have not yet checked for a change in miles-per-gallon. Even if that were unchanged, the smoother acceleration with its quicker response from the gas pedal is wonderful.

PapaMattK,
Laguna Hills, California

After installing this air system (57-1537) on my 2007 Ram 1500 with a 3.7L engine I was VERY upset@! &nbsp;Up set that this is not standard on the vehicle from the manufacturer!!! What a performance difference, should be shipped from the factory with this product. &nbsp;Better performance and better gas milage, about 4mpg!<br />
<br />
For me this was a two step process. I was not sure about how this would work, so I first simply bought the air filter replacement element and installed in the factory air cleaner. &nbsp;Right away I noticed a difference. &nbsp;So much so that I bought another one for my wife's car (2002 Hyundai). &nbsp;After running with the air filters for a while, I decided to look into the air-system replacement. It took a few months for me to actually buy the system because I guess my truck in not a true 2007 but a 2007-1/2 or 2007-3/4. &nbsp;The actual engine configuration is that of a 2008. &nbsp;So when I down loaded the install manual from K & N's web site the crank case breather did not look like the 2007 described. &nbsp;Once I determined that my engine confirguration looked more like a 2008 I was home free. &nbsp;I bought the unit and just love the performance!! &nbsp;With the price of gas as it is I love the extra 4 mpg as well.

Paul ,
Kansas

Got my KN Filter in April. I drive a 2005 Hyundia was getting 28 mpg. After the filter was installed, which was easy, I am now getting over 31 mpg